Which of the following is not an endothermic reaction?

Explanation:

Endothermic reactions are chemical processes in which the reactants absorb heat energy from the environment to produce products. These reactions cause a cooling effect by lowering the temperature of their surroundings. Endothermic reactions, in general, include the creation of chemical bonds as a result of heat absorption from the environment.

In A and B heat is absorbed in order to complete the reaction.

In C, the reaction is the burning of glucose which releases energy. It is an exothermic reaction.

Final Answer:

Hence, option C is correct i.e: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6 H₂O is not an endothermic reaction.